| 摘要 |
PROBLEM TO BE SOLVED: To provide a transistor using an oxide semiconductor film in which a threshold voltage becoming minus is reduced, and to provide a semiconductor device with high quality having the transistor using the oxide semiconductor film.SOLUTION: An oxide semiconductor film having first to third regions is used for a transistor. In the first region, the oxide semiconductor film is in contact with a source electrode or a drain electrode on a top surface, in the second region, the film is in contact with a protective insulating film on the top surface and has a substantially even film thickness with a smaller thickness than the maximum film thickness in the first region, and in the third region, the film is in contact with the protective insulating film on the top surface and side surfaces. |
